PEORIA — Peoria Public School District 150 has reported potential irregularities in the administration of the ISAT test at Charter Oak Primary School to the Illinois State Board of Education.

The district issued a statement late Tuesday after a Journal Star inquiry into whether Charter Oak Principal John Wetterauer had been placed on administrative leave. District 150 spokesman Chris Coplan would not confirm Wetterauer's circumstances, though other sources did.

The issue heated up Wednesday morning as Charter Oak parents and other Wetterauer suppporters pledged to support the long-time principal.

Wetterauer's attorney, Nile Williamson, also released a response on Wetteraurer's behalf.

"It is noteworthy that the district has, to date, taken no disciplinary action against the two teachers who administered the allegedly tainted tests," Williamson said."We are disappointed that the district, based on these facts, would choose to take disciplinary action against one of its most outstanding principals."

Charter Oak, consistently one of District 150's higher-performing schools on the Illinois Standards Achievement, was named a National Blue Ribbon School in 2012, one of only 269 in the country. It was one of only four District 150 schools that made adequate yearly progress on the more rigorous 2013 state standardized test.

A pattern of inconsistencies between ISAT scores and academic achievement of Charter Oak's special education students prompted the district to begin a preliminary investigation and contact the state board.

According to the district's statement, which did not name Wetterauer, the irregularities date from the 2008-2009 school year to the most recent academic year.

"While we anticipate that it may take some time for ISBE to consider this matter, we will work closely with them to enact the necessary measures to ensure that all future assessments at Charter Oak and throughout all District 150 schools are administered in accordance with the mandatory testing protocols," District 150 Supt. Grenita Lathan said in the statement.

"We take these allegations very seriously, and felt it was our duty and responsibility to be forthcoming and transparent about this matter with our parents, faculty and community."

According to Williamson, District 150 began investigating ISAT scores for students of two Charter Oak special education teachers about a month ago.

"Mr. Wetterauer was not advised of any personal involvement by the district, cooperated fully in the investigation, and offered to take a polygraph," Williamson said.

The tests are conducted in a closed classroom and a District 150 administrator inspects the classroom, Williamson continued. Wetterauer is not present during the test.